Pep Guardiola hailed Bristol City's tactics after Manchester City needed a stoppage-time header from Sergio Aguero to claim a 2-1 win in Tuesday's EFL Cup semi-final first leg.

The Championship side – who knocked out Manchester United in the last round – led at the interval thanks to a Bobby Reid penalty that the striker won himself after being fouled by John Stones.

But Manchester City improved markedly in the second period, captain Kevin De Bruyne levelling 10 minutes after the break before Aguero came off the bench to head in Bernardo Silva's pinpoint cross.

While the runaway Premier League leaders dominated possession, the match was far from a procession and Guardiola believes the visitors' willingness to attack made the game a more entertaining contest.

"It is all benefit for football, for the fans, for everyone, when two teams want to play," Guardiola said after his side extended their unbeaten domestic run to 32 games.

"That makes sure it is going to be a good match and it is up to us to find a way to beat the opponent. We face all kinds of teams this season and play in all ways, but we have always found the formula to beat them.

"[It was a] nice game, beautiful game, all my credit to Bristol. You cannot knock out four teams from the Premier League without being well organised and having nice players to watch. It is fantastic.

"I am a lucky guy to train the players I have. Always semi-finals are tough, 1-0 down and how we reacted.

"I don’t know what is going to happen at the end of the season, but I respect these professionals as human beings. They give everything.

"Manchester City fans here around the world must be so proud. It will be tough in Bristol.

"In the Champions League it will be similar, you cannot play 180 minutes always in control. It is okay, we are going to try and play there and make the final."

Guardiola started the game without a recognised striker as Aguero was rested having started against Burnley in the FA Cup, while Gabriel Jesus is injured.

But the Catalan – who would not confirm City's reported interest in a January move for Arsenal forward Alexis Sanchez – believes he has various central attacking options in his squad, with Silva and Raheem Sterling alternating in the role against the Robins.

"Bernardo played there many times and [Sterling] when we play five at the back. Of course it is not their natural position," said Guardiola.  

"They do not have the feeling like Sergio and Gabriel for goal, but we have to rotate and everyone is involved. Except David Silva, all the players play in the competition. Fernandinho has a million minutes in his legs so sometimes we have to use other options.

"We created a lot of chances. Of course Sergio had a lot of games in there. With the situation Gabriel is not fit, we have to protect him a bit. Sergio is on fire, scoring goals again but always in his career he scores goals. But we create chances.

"We were there a lot if you analyse how many times we shoot and hopefully in the second leg we can score more goals."